Air or other gas filtering is desirable in a number of systems. A typical application is in the filtration of intake air to internal combustion engines. Another is in the filtration of crankcase ventilation filter assemblies. Typically, such systems comprise filter assemblies having a serviceable filter cartridge therein. After a period of use, filter media within a filter housing requires servicing, either through cleaning or complete replacement. Typically, for an air cleaner or crankcase ventilation filter assembly used with an internal combustion engine, for example, on a vehicle, the filter media is contained in a removable and replaceable, i.e. serviceable, component, typically referred as a filter element or cartridge. The filter cartridge is configured to be removably sealed within the air cleaner, in use. Improvements in filter arrangements relating to assembly, serviceability, and/or use are desirable. The filter cartridge can be provided as a first (e.g., primary) filter cartridge or a second (e.g., secondary or safety) filter cartridge. The air cleaner assembly can contain only a first filter cartridge or both a first filter cartridge and a second filter cartridge.